Optical gas sensor

Abstract

This application provides an optical gas sensor, which includes a housing, a light source, and a detection probe. The optical gas sensor has an optical chamber and a metal coating. The housing includes an inner wall and an outer wall, with the metal coating at least partially attached to the inner wall. The housing has a first through-hole communicating with the optical chamber and with external gas. The housing comprises a first housing and a second housing, which are separately configured and then fitted together. This method simplifies the metal coating process, ensures uniform coating distribution, and improves the reflection of light emitted by the light source from the inner wall of the housing, thereby enhancing the detection accuracy of the optical gas sensor. A method for manufacturing an optical gas sensor involves electroplating metal onto the inner wall of at least one of the first and second housings, and then assembling the first and second housings.

Description

Technical Field

[0001] This application relates to the field of sensing technology, and more particularly to an optical gas sensor used in a refrigeration system. Background Technology

[0002] The related optical gas sensor includes a housing, a light source, and a detection probe, the detection probe being able to receive light emitted by the light source. The housing has an optical chamber and a first through-hole through which gas can enter the optical chamber. The gas to be measured affects the light emitted by the light source, and the sensor detects the gas to be measured by the changes in the light received by the detection probe.

[0003] In related technologies, a metallic reflective layer is coated on the inner wall of the housing. The purpose is to reflect a portion of the light emitted by the light source back to the detection probe after reaching the housing, thereby improving the detection accuracy of the optical gas sensor. However, the reflection effect of the light emitted by the light source on the inner wall of the housing in these technologies is not ideal. Summary of the Invention

[0004] The inventors discovered that the poor reflection effect of the light emitted by the light source on the inner wall of the shell was caused by the uneven coating of the metal reflective layer. One of the reasons for the uneven coating of the metal reflective layer is that the shell is integrally formed, making it difficult to coat the metal reflective layer onto the inner wall of the optical cavity.

[0005] Therefore, this application provides an optical gas sensor, which includes a housing, a light source, and a detection probe. The housing has an optical chamber, and the optical gas sensor includes a metal coating. The housing includes an inner wall surface and an outer wall surface, with the inner wall surface closer to the optical chamber than the outer wall surface. The metal coating is at least partially attached to the inner wall surface. The housing has a first through hole that communicates with the optical chamber and with external gas. The housing includes a first housing and a second housing, which are fixedly connected or limit-connected.

[0006] The first housing and the second housing are fixedly connected or limited to each other. Before the first housing and the second housing are fixedly connected or limited to each other, the inner walls of the first housing and the second housing are electroplated with metal coatings, and then the first housing and the second housing are connected. This makes the operation of applying the metal coating easier, which is conducive to the uniform application of the metal coating. The reflection effect of the inner wall of the housing on the light emitted by the light source is improved, thereby improving the detection accuracy of the optical gas sensor.

[0007] This application also provides a method for manufacturing an optical gas sensor, the method comprising the following steps: providing a first housing and a second housing; electroplating metal onto the inner wall surface of at least one of the first housing and the second housing to form a metal coating; assembling the first housing and the second housing together to obtain an optical chamber. This method of applying the metal coating is easy, facilitates uniform coating, and improves the reflection effect of the inner wall of the housing on light emitted by the light source, thereby improving the detection accuracy of the optical gas sensor. Attached Figure Description

[0008] Figure 1 A three-dimensional schematic diagram of an optical gas sensor provided in one embodiment of this application;

[0009] Figure 2 for Figure 1 The diagram shows an explosion of an optical gas sensor.

[0010] Figure 3 An explosion diagram of an optical gas sensor provided for another embodiment of this application;

[0011] Figure 4 for Figure 1 A schematic cross-sectional view of the optical gas sensor shown.

[0012] Figure 5 for Figure 1 A partial structural schematic diagram of the optical gas sensor is shown.

[0013] Figure 6 for Figure 3 A schematic diagram of an optical gas sensor exploding from another angle;

[0014] Figure 7 for Figure 1 The diagram shows a partial structural schematic of the optical gas sensor. Detailed Implementation

[0015] To better understand the technical solution of this application, the technical solution of this application will be described in detail below with reference to the accompanying drawings.

[0016] It should be understood that the described embodiments are only some embodiments of this application, and not all embodiments. Based on the technical solutions in this application, all other technical solutions obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0017] The optical gas sensor 100 of the related technology includes a housing 200, a light source 101, and a detection probe 102. The housing contains an optical chamber 103, where the light source 101 and the detection probe 102 are located. The housing has a first through-hole 21 structure, through which gas enters the optical chamber 103 from the outside and is detected by the detection probe 102. To save costs, the housing is made of plastic instead of metal. To improve light utilization, a metal coating 53 is applied to the walls of the optical chamber 103, thus ensuring that the detection accuracy of the optical gas sensor 100 is not affected. However, because the housing is integrally molded, applying the metal coating 53 to the walls of the optical chamber is difficult, resulting in uneven coating and affecting the detection accuracy of the optical gas sensor.

[0018] The optical gas sensor 100 of this application includes a housing 200, a light source 101, and a detection probe 102. The optical gas sensor 100 has an optical chamber 103, and the housing 200 is part of the wall of the optical chamber 103. The optical gas sensor 100 includes a metal coating 53. The housing 200 includes an inner wall surface 24 and an outer wall surface 25. The inner wall surface 24 is closer to the optical chamber 103 than the outer wall surface 25. The metal coating 53 is at least partially attached to the inner wall surface 24. The housing 200 has a first through hole 21, which communicates with the optical chamber 103 and with the external gas of the optical gas sensor 100. The housing 200 includes a first housing 20 and a second housing 30, which are separately configured and are fixedly connected or limitedly connected. The first housing 20 and the second housing 30 are separate units. Before connecting the first housing 20 and the second housing 30, a metal coating 53 can be applied to the inner walls of both housings. Then, the first housing 20 and the second housing 30 can be fixedly connected or limited in place. This reduces the difficulty of applying the metal coating 53, ensures uniform coating, and improves the light reflection effect of the inner wall surface 24 on the light emitted by the light source, thereby improving the detection accuracy of the optical gas sensor. Specifically, at least one of the first housing 20 and the second housing 30 has a first through hole 21. The first through hole 21 communicates with the optical chamber 103 and with the external gas of the optical gas sensor 100, allowing the external gas to enter the optical chamber 103 through the first through hole 21. In one embodiment, the number and shape of the first through holes 21 are not defined, such as... Figure 5 As shown, there are eight first through holes 21.

[0019] To improve the light utilization rate during detection by the optical gas sensor 100, in one embodiment, such as Figure 4As shown, the optical gas sensor 100 includes a condenser cup 104, which is connected to the second housing 30. The condenser cup 104 is part of the wall of the optical chamber 103. Along the length L of the optical gas sensor 100, the detection probe 102 and the condenser cup 104 are located at opposite ends of the optical chamber 103. The condenser cup 104 and the light source 101 are located on the same side of the optical chamber 103. In another embodiment, as shown... Figure 3 As shown, in order to facilitate installation and improve the airtightness of the optical chamber 103, the condenser cup 104 and the second housing 30 are integrated as one piece.

[0020] Furthermore, in one embodiment, such as Figure 4 As shown, the optical gas sensor 100 has a hole 105, and a hole 51 penetrates the condenser cup 104. A portion of the light source 101 is located in the hole 51; the light source 101 is sealed to the wall corresponding to the hole 51. Specifically, the condenser cup 104 includes a surface 52, which is part of the wall surface of the optical chamber 103, and the surface 52 is curved. The curved surface improves the focusing effect; a parabolic surface is preferred. When the condenser cup 104 and the second housing 30 are integrally formed, the condenser cup 104 is made of plastic, and a metal coating 53 is attached to the surface 52.

[0021] In one embodiment, the metal coating 53 includes any one of a nickel coating, a gold coating, or a chromium coating, wherein a nickel coating is less expensive than a gold coating and has comparable reflective properties. In another embodiment, the housing 200 is a plastic part, the plastic including a mixture of polycarbonate and polyacrylonitrile.

[0022] In one embodiment, as shown in FIG. X6, the second housing 30 includes a main body 34 and a first positioning part 32. Along the length direction L of the optical gas sensor 100, the first positioning part 32 protrudes from the main body 34 in a direction away from the optical chamber 103. The optical gas sensor 100 includes a probe circuit board 61, and a detection probe 102 is electrically connected to the probe circuit board 61. Specifically, the probe circuit board 61 has a second through hole 612, and the first positioning part 32 is at least partially located in the second through hole 612, and the first positioning part 32 is fixedly connected to the wall of the second through hole 612. In one embodiment, the detection probe 102 is electrically connected to the probe circuit board 61.

[0023] In another embodiment, such as Figure 7As shown, the detection probe 102 includes a body portion 651 and a second positioning portion 652, which is perpendicular to the length direction L of the optical gas sensor 100. The second positioning portion 652 protrudes from the body portion 651 in a direction away from the optical chamber 103. At this time, the first housing 20 has a second groove 23. Along the length direction L of the optical gas sensor 100, the second groove 23 is recessed along the wall of the first housing 20 in a direction closer to the light source 101. The second positioning portion 652 is at least partially located in the second groove 23. The design of the second positioning portion 652 and the second groove 23 makes the installation of the first housing 20 more convenient and accurate. The second positioning portion 652 also plays a role in preventing mistake-proofing.

[0024] The optical gas sensor 100 includes a light source circuit board 62, and the light source 101 is electrically connected to the light source circuit board 62; specifically, in one embodiment, such as Figure 3 As shown, the second housing 30 includes a third positioning portion 33, which protrudes from the main body 34 and away from the detection probe 102 along the length direction L of the optical gas sensor 100; the light source circuit board 62 has a third through hole 62, and the third positioning portion 33 is at least partially located in the third through hole 621; the third through hole 62 penetrates the light source circuit board 62, and the number and shape of the third positioning portions 33 are not defined, but the shape and number of the third through holes 62 correspond one-to-one with the third positioning portions 33. In another embodiment, as... Figure 3 As shown, the focusing cup 104 includes a third positioning part 33.

[0025] The optical gas sensor 100 includes a first waterproof and breathable membrane 71, a flow guide 73, a housing 70, and a main circuit board 74. The first waterproof and breathable membrane 71 is aligned with a first through-hole 21. The first waterproof and breathable membrane 71 is used to prevent water or dust from entering the optical chamber 103. In one embodiment, the first waterproof and breathable membrane 71 is located in the optical chamber 103. In another embodiment, the first waterproof and breathable membrane 71 is located outside the optical chamber 103, that is, the first waterproof and breathable membrane 71 is far away from the optical chamber 103 relative to the first through-hole 21. The first waterproof and breathable membrane 71 is connected to the first housing 20. Here, the connection method between the first waterproof and breathable membrane 71 and the first housing 20 is not defined. In another embodiment, the first waterproof and breathable membrane 71 directly covers the first through-hole 21.

[0026] Both the light source 101 and the detection probe 102 are electrically connected to the main circuit board 74; specifically, for ease of installation, in one embodiment, such as Figure 4 As shown, the light source 101 is electrically connected to the light source circuit board 62, the detection probe 102 is electrically connected to the probe circuit board 61, and both the probe circuit board 61 and the light source circuit board 62 are electrically connected to the main circuit board 74. Along the length L of the optical gas sensor 100, the probe circuit board 61 and the light source circuit board 62 are located at both ends of the main circuit board 74.

[0027] In one implementation, such as Figure 1 and Figure 4 As shown, the housing 70 has a cavity 701 and a fourth through hole 702, which penetrates the housing 70 and connects the cavity 701 to the outside of the optical gas sensor. In one embodiment, the optical gas sensor 100 includes a second waterproof and breathable membrane 72, which is at least partially aligned with the fourth through hole 702. The second waterproof and breathable membrane 72 is used to prevent moisture and dust from entering the cavity 701 and thus affecting the detection accuracy of the optical gas sensor 100.

[0028] Specifically, in one implementation, such as Figure 2 As shown, the first waterproof and breathable membrane 71, the flow guide 73, the main circuit board 74, the first housing 20, and the second housing 30 are all located in the cavity 701. The flow guide 73 is at least partially located between the fourth through hole 702 and the first through hole 21. The flow guide 73 concentrates the gas into the optical cavity 103, improving the detection efficiency of the optical gas sensor 100.

[0029] like Figure 5 and Figure 6 As shown, the flow guide 73 has a fifth through hole 731, which communicates with the fourth through hole 702 and the first through hole 21. The flow guide 73 includes a flow guide plate 732, which is part of the wall of the fifth through hole 731 and is inclined. Specifically, in one embodiment, the flow guide plate 732 includes a first part 7321 and a second part 7322. The first part 7321 is closer to the first through hole 21 than the second part 7322. Along the length direction L of the optical gas sensor 100, the first part 7321 is farther away from the main circuit board 74 than the second part 7322.

[0030] To facilitate the assembly of the optical gas sensor 100, in one embodiment, such as Figure 1 As shown, the outer casing 70 includes a first outer casing 703 and a second outer casing 704.

[0031] The optical gas sensor 100 includes a sealing ring 75, and a first housing 703 and a second housing 704 are sealed by the sealing ring 75.

[0032] A method for manufacturing an optical gas sensor includes the following steps: providing a first housing 20 and a second housing 30; electroplating metal onto the inner wall surface 24 of at least one of the first housing 20 and the second housing 30 to form a metal coating 53; wherein, after electroplating the metal onto the inner wall surface 24 of at least one of the first housing 20 or the second housing 30, it needs to be cleaned and dried to finally form the metal coating 53. The first housing 20 and the second housing 30 are then assembled to obtain an optical chamber 103. By electroplating metal onto the inner wall surface of at least one of the first housing and the second housing before assembling them, the metal coating process is simplified, the light reflection effect emitted by the light source within the optical chamber 103 is improved, the metal coating is more uniformly applied, and the detection accuracy of the optical gas sensor is improved.

[0033] Furthermore, in one embodiment, after electroplating metal onto the inner wall surface 24 of at least one of the first housing 20 and the second housing 30 to form a metal coating, the following steps are included: providing a light source 101 and a detection probe 102; welding the first housing 20 and the second housing 30 together; assembling the light source 101 with the second housing 30, and assembling the first housing 20 and the second housing 30 with the detection probe 102 respectively, such that both the light source 101 and the detection probe 102 are located in the optical cavity 103. Finally, energizing the light source 101 and the detection probe 102.

[0034] Specifically, in one implementation, such as Figure 2 As shown, the first through hole 21 penetrates the first housing 20. The first housing 20 includes a protrusion 221, which protrudes along the wall of the first housing 20 relative to the first through hole 21 and toward the second housing 30. Specifically, the protrusion 221 may be elongated or ridged. The second housing 30 has a first groove 311, and the protrusion 221 is at least partially located in the first groove 311. The first housing 20 and the second housing 30 are welded together. During welding, the protrusion 221 melts and fills the first groove 311.

[0035] Specifically, in another implementation, such as Figure 3 As shown, the optical gas sensor 100 includes a first edge portion 22, which is located around the periphery of the first housing 20 and connected to the first housing 20. The first edge portion 22 includes a protrusion 221. The first edge portion 22 is flat. To ensure a more secure connection between the first housing 20 and the second housing 30, there are two first edge portions 22, located symmetrically on both sides of the first housing 20. In contrast, as... Figure 3As shown, the optical gas sensor 100 includes a second edge portion 31, which is located around the second housing 30 and connected to the second housing 30. The second edge portion 31 has a first groove 311.

[0036] Some of the technical features in the above embodiments can be combined or replaced.

[0037] Although this application has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still make modifications or equivalent substitutions to this application without departing from the spirit and scope of this application.

Claims

1. An optical gas sensor, characterized in that, The optical gas sensor (100) includes a housing (200), a light source (101), and a detection probe (102). The housing (200) has an optical chamber (103). The optical gas sensor (100) includes a metal coating (53). The housing (200) includes an inner wall surface (24) and an outer wall surface (25). The inner wall surface (24) is closer to the optical chamber (103) than the outer wall surface (25). The metal coating (53) is at least partially attached to the inner wall surface (24). At least a portion of the light source (101) and at least a portion of the detection probe (102) are located in the optical chamber (103). The housing (200) has a first through hole (21), which communicates with the optical chamber (103) and with the external gas of the optical gas sensor (100). The housing (200) includes a first housing (20) and a second housing (30), which are fixedly connected or limitedly connected.

2. The optical gas sensor according to claim 1, characterized in that, The optical gas sensor (100) includes a condenser cup (104), which is connected to the second housing (30) and is part of the wall of the optical chamber (103); The focusing cup (104) and the second housing (30) are an integral part.

3. The optical gas sensor according to claim 2, characterized in that, The optical gas sensor (100) has a hole (51) that penetrates the condenser cup (104), and the light source (101) is partially located in the hole (51); The focusing cup (104) includes a surface (52), which is part of the wall of the optical chamber (103), and the surface (52) is an arc surface.

4. The optical gas sensor according to claim 1, characterized in that, The metal coating (53) is attached to at least one of the first housing (20) and the second housing (30). The metal coating (53) includes any one of a nickel coating, a gold coating, or a chromium coating; The housing (200) is made of plastic.

5. The optical gas sensor according to claim 2, characterized in that, Along the length of the optical gas sensor (100), the detection probe (102) and the condenser cup (104) are located at opposite ends of the optical chamber (103), and the condenser cup (104) and the light source (101) are located on the same side of the optical chamber (103). The second housing (30) includes a main body (34) and a first positioning part (32). Along the length direction of the optical gas sensor (100), the first positioning part (32) protrudes from the main body (34) in a direction away from the optical chamber (103). The optical gas sensor (100) includes a probe circuit board (61), the detection probe (102) is electrically connected to the probe circuit board (61), the probe circuit board (61) has a second through hole (612), the first positioning part (32) is at least partially located in the second through hole (612), and the first positioning part (32) is fixedly connected to the wall of the second through hole (612).

6. The optical gas sensor according to any one of claims 1-5, characterized in that, The optical gas sensor (100) includes a light source circuit board (62), and the light source (101) is electrically connected to the light source circuit board (62); The second housing (30) includes a third positioning part (33), which protrudes from the main body (34) and away from the optical chamber (103) along the length direction of the optical gas sensor (100). The light source circuit board (62) has a third through hole (621), and the third positioning part (33) is at least partially located in the third through hole (621).

7. The optical gas sensor according to any one of claims 1-5, characterized in that, The detection probe (102) includes a body part (651) and a second positioning part (652), wherein the second positioning part (652) protrudes from the body part (651) in a direction away from the optical cavity (103); The first housing (20) has a second groove (23) along the length of the optical gas sensor (100). The second groove (23) is recessed along the wall of the first housing (20) toward the light source (101). The second positioning part (652) is at least partially located in the second groove (23).

8. The optical gas sensor according to any one of claims 1-5, characterized in that, The optical gas sensor (100) includes a first waterproof and breathable membrane (71), a housing (70), and a main circuit board (74); The first waterproof and breathable membrane (71) is aligned with the first through hole (21); The light source (101) and the detection probe (102) are both electrically connected to the main circuit board (74); The outer shell (70) has a cavity (701) and a fourth through hole (702), the fourth through hole (702) connecting the cavity (701) and the outside of the optical gas sensor. The first waterproof and breathable membrane (71), the main circuit board (74), the first housing (20) and the second housing (30) are all located in the cavity (701).

9. A method for manufacturing an optical gas sensor, characterized in that, The manufacturing method includes the following steps: A first housing (20) and a second housing (30) are provided; Metal is electroplated onto the inner wall surface (24) of at least one of the first housing (20) and the second housing (30) to form a metal coating (53); The first housing (20) and the second housing (30) are assembled together.

10. The method for manufacturing an optical gas sensor according to claim 9, characterized in that, After electroplating metal onto the inner wall surface (24) of at least one of the first housing (20) and the second housing (30) to form a metal coating, the following steps are included: Provides a light source (101) and a detection probe (102); The light source (101) is assembled with the second housing (30), and the first housing (20) and the second housing (30) are respectively assembled with the detection probe (102).

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